Field of the Invention
The present invention relates to an active damping system having an electric motor for a vehicle, in which a damper is actuated in different ways depending upon traveling situations, thereby maintaining a stable contact between a road and wheels, and thus improving braking power, steering feel, and riding comfort.
Specifically, the present invention relates to an active damping system having an electrically controlled actuator that is differently controlled depending upon a traveling mode of a vehicle, and more particularly, to a technology of actuating a damper in a passive mode under a general traveling situation in which there are little changes in behavior of a vehicle body, while actuating the damper in an active mode in a case where a great change is shown in the behavior of the vehicle body, so that this provides a smooth and predictable ride quality, increasing safety and comfort.
Background of the Related Art
Suspension technology has developed rapidly since the beginning of 1900s. Earls S. MacPherson developed the MacPherson strut in 1950s, and Colin Chapman, who founded the sports car company Lotus Cars, developed an active damper in 1980s. His innovations gained popularity in Formula 1 because of reducing a handling defect caused by advancement in aerodynamic design.
A control system for the active damper is designed to maintain a contact force between the tire and the road, while minimizing the pitch and roll of the vehicle body in straight-line and cornering conditions. Also, the control system provides a damping function to minimize the effect of the impact of the tire against the road. This impact is produced by the pitch of the tire when it comes into contact with the recesses formed on the road, and has a jarring effect on occupants in the vehicle.
The conventional active damping system is designed to operate even while traveling on the generally straight road which causes little change in the behavior of the vehicle body. Although the passive damper can sufficiently maintain the stability of the vehicle body, the electrically controlled actuator is constantly being activated, which consumes the power and generates a lot of heat.